Antarctica’s ice isn’t stuck tight, frozen onto the continent like frigid glue. In many places, liquid water sits between the ice and the ground beneath it. This water forms because heat seeping from inside the Earth gradually melts away the bottom of the ice sheet. Layers of water, thinner than a few stacked coins, melt off of the bottom of the ice each year. This water collects in low places, forming lakes. The water flows from one lake to another. Eventually it empties into the ocean.